I've read a story of a 3 year old that had to have his tonsils removed. The poor child didn't understand that it's not good to swallow so much blood, didn't know enough to tell his parents what was up, and he unfortunately passed away, with a belly full of blood ☹️
Absolutely not true. Wherever you read it is full of malarkey. I would go so far as to say it is impossible, since your be vomiting unless you were still drugged. It would take sedatives to keep you under long enough to swallow that much, and you can still vomit while sedated.
You also don't die from a full belly by itself.
Then, there's the fact that the stomach takes up some degree of water during digestion, and is breaking down any solids that it can break down along the way. You'd have to literally chug the blood to get enough in at once to distend the stomach, and no tonsillectomy produces that much blood.
Almost every single modern procedure uses some kind of cautery to stop bleeding, and the few that don't still take steps to do so.
Anyone, especially a small child, bleeding enough to die from swallowing it, would never be sent home. That's a sign of a major problem apart from the surgery.
And that's ignoring how much blood loss that would be. Even if swallowed, the amount needed to cause death wouldn't fill the stomach in a small child. Even in a bigger child, the stomach is bigger too, so you run into issues with realism there.
Tonsilectomies are done all around the world, and have been for ages. While complications can happen, this simply isn't one of them.
I can't quite find the much older story of the 3 year old toddler though, but it was essentially the same thing, and took about a week of health decline before he passed. Nobody knew the toddler was swallowing the blood until the autopsy ☹️
The poor child didn't understand that it's not good to swallow so much blood
It sounds like the swallowing wasn't the problem, the bleeding was. The swallowing just masked the true symptom, the bleeding, from being observed by others.